Controller unit



NOV. 18, 1952 5, ROSSlRE 2,618,446

CONTROLLER UNIT Filed April 29, 1946 3 Sheets-Sheet 2 Nov. 18, 1952 F. H. s. ROSSIRE CONTROLLER UNIT 3 Sheets-Sheet 3 Filed April 29, 1946 [NVENTOR E HENRY 5. REES/HE @ORNEY Patented Nov. 18, 1952 CONTROLLER UNIT F. Henry S. Rossire, Leonia, N. J., assignor to Bendix Aviation Corporation, Teterboro, N. J a corporation of Delaware Application April 29, 1946, Serial No. 665,918

14 Claims. 1

This invention relates generally to automatic pilot or steering systems for mobile craft and more particularly to novel automatic trim and/or turn provisions therefor and as such constitutes an improvement over the automatic trim and/or turn control unit of copending application Serial No. 604,861 filed July 13, 1945, now U. S. Patent No. 2,516,641, issued July 25, 1950.

An object of the present invention is to provide a novel, improved and simplified control unit for automatic steering systems.

Where previously, as represented by the control unit of the aforementioned application, the pitch trim and bank trim knobs were arranged for motion about parallel fore and aft craft axes, in the unit of the present invention the bank trim knob only is mounted on the controller for motion about an axis parallel with the fore and aft axis, while the pitch trim knob is mounted on the controller for motion about a transverse axis, 1. e., one parallel with the axis of oscillation of the elevator which it controls so that movement of the pitch trim knob toward the operator will provide an up-elevator condition while a reverse motion of the knob will provide a down-elevator condition. Thus, the novel arrangement hereof is of considerable importance to the human pilot since movement by him of the pitch trim knob will be the same as the movement imposed on the elevator by a conventional control column utilized in mobile craft.

Another object of the present invention, therefore, is to provide a novel controller unit for automatic steering systems for mobile craft wherein each control, i. e., pitch trim, bank trim and auto- 'i'natic turn is angularly displaceable about an axis parallel with the axis of movement of the related control surface or surfaces. For example, pitch trim control is accomplished by adjustment about an axis parallel to the craft transverse axis,

bank trim control is accomplished by adjustment about an axis parallel to the craft fore and aft axis, while automatic turn is provided through a handle pivoted for angular displacement about the craft fore and aft axis or the axis of craft turn.

Furthermore, in the controller unit of the aforementioned application, a switching mechanism was provided for disconnecting the compass from the rudder channel operable in response to the displacement of the controller unit turn knob so that a time lag was developed bet-ween aileron and rudder response to turn signals tending toward uneven craft flight. With the unit of the present invention, on the other hand, the =7 handle for automatic turn control is provided with a trigger mechanism which is grasped by the pilot at the time of handle displacement so that aileron and rudder channels respond substantially simultaneously to the generated turn signals whereby smoother craft flight is acquired thereby. Moreover, as a result of such novel arrangement more accurate rudder trim or course setting is available.

A further object of the invention, therefore, is is to provide a novel automatic turn control mechanism for automatic steering systems whereby smoother craft flight control is provided thereby than that heretofore available and whereby more accurate rudder trim is possible.

With the controller unit of the present invention, the amount of gearing heretofore required has been reduced to a minimum eliminating thereby lost motion between the controls and the related signal generators, back lash, etc.

Another object of the invention is to provide a novel controller unit for an aircraft automatic pilot whereby in response to manual adjustments of controls on the front of the unit, pitch, bank and rudder signals can be modified and the craft made to execute coordinated maneuvers while with the turn adjustments centered the craft will assume straight flight.

The above and other objects and advantages of the present invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the invention is illustrated.

In the drawings wherein like reference characters refer to like parts throughout the several views:

Figure l is a diagrammatic illustration of an automatic steering system for mobile craft embodying the novel automatic trim and/or turn control unit of the present invention;

Figure 2 is a detailed schematic illustration of the novel trim and/or turn controller unit of the present invention;

Figure 3 is a front elevation view of one practical embodiment of the control panel for operating the automatic trim and/or turn mechanism; and,

Figure 4 is a side elevation view of the turn panel of Figure 3 illustrating the arrangement of the turn, bank and pitch knobs thereon.

Referring now to the drawings for a more detailed description of the present invention and more particularly to Figure 1 thereof, it is there shown as embodied in an all electric automatic gyro [3 adapted for generating an electrical signal proportional to the rate of turn which issuperimposed upon the direction signalto modify the energization of the rudder servo system H and an artificial horizon gyro 14' having bank and pitch take-offs l5 and 6 for generating signals in proportion to the bank and pitch of the-Zcraft for energizing aileron and elevators l9 and 26.

As pointed out more fully in copending application Serial No. 516,488, the magnetic field pick-up device for generating an electrical signal proportional to the amount of craft deviation fromia prescribed course comprises a triangular element 2tl having three: laminated legs, each of which-is provided with a pair of exciting orprimaryrwindings' 22, 23 connected in series opposed relation with each other and with asuitable source of alternating current (not shown) by wayof leads '24 and 2.5. Wound in inductive relation to the first coils, is a delta connected coil 26, which may be termed the secondary winding of the device; Coil 26 is provided with threetapsforconnecting it' by Way of leads 2?- with a three phase Wound stator. 28 ofan inductive coupling device 29 suitablymounted within a master indicator, 39;

Coupling device 29 is provided with an angularly movab'le'rotor 3i inductivelyassociated with the stator windings; 23 and carried by a shaft 32 for angular motion relative thereto. Winding}! is connected to the input or a conventional vacuum tube amplifier 33 by way of leads 3d, the output of. the amplifier feeding by way of leads 35 to one phase winding 36 of a two phase induction motor 31, the second phase winding- 33 of which connects with a source of A. C. current through a suitable frequency doubler 39, the latter also being provided with a conventional phase shifting network to maintain the voltages within the two phase windings substantially 90 apart as i known in the use of such motors.

Motor 3"! has a rotor ll carried by a shaft 4| provided at its outer end with apinicn t2 adapted for driving through a speed reduction gear system G3, a gear 4d fastened to rotor shaft 32. A

gear t5, supported by the free end of shaft 32,

meshes with a gear 4-6 having connected thereto or formed integrally therewith a hollow shaft er 7 supporting by way of an arm dB the shaft of a worm i9. which meshes with a worm 58 formed or carried by a spindle shaft 51 which is received within hollow shaft 5?. An annular compensator 52 having a series of adjusting screws 53 in engagement therewith is contacted by a follower 54 supported by an arm 55 fastened to the shaft of worm 9. Thus, in addition to motion imparted by rotor shaft 32 to spindle shaft 5%, the latter is moved a small angular amount in one direction or another depending upon the contour of element 52 engaged by follower 54.

An indicating dial se is mounted on one end of spindle shaft 5! for cooperation with a fixed index 5'! while the opposite end of the spindle is provided with a gear .53 for meshing with a gear 59' carried by a shaft 66 supporting a magnetic rotor 61 thereon which is magnetically coupled magnetic material.

with a stator winding 62 of an electromagnetic transmitter, the latter being adapted for connection to a similar device as a receiver located at a remote station to reproduce the indication of heading.

The free end of rotor shaft 32 carries through a resilient supporting member 63 a clutch face 6%, a cooperating clutch face 65 being supported by a shaft 86, both clutch faces being formed of A coil 6'! surrounds the clutch faces and has one end thereof grounded as at 68: and the other end thereof connected with a battery 69 by way of a pair of series connected normallyclosedcontrol switches at the novel controller unit, hereof to be hereinafter described, a lead 10, contacts ll of a servo clutch switch 12 and; contacts l3? of a power switch 14.

Upon .closing of switches 12 and 14 as well as the control switches at the controller unit, coil 61 is energized and clutch faces 64, 65 are brought intodriving engagement whereby any motion of sha-ft32 is immediately transmitted to shaft 66 whichalso supports thereon; for angular motion there-with, a rotor winding inductively.- asseciated witha threephase wound: stator lid. of an inductive-transmittingdevice H In order to obtain automatic synchronization of controls, two lever armsl-flzand leareprovided within the master direction indicator which are pivoted on fixed pins and 8| and interconnected through a resilient. member 82 anchored to both arms slightly below pivot pins '80 and 8|. A bracket 83 is fastened to shaft. it and is pro,- vided witha pin positioned in betweenrarmslii and '19 sothat uponclockwise rotationufshaftfifi; for example, pin 84' will move arm 19 outwardly when a turning torque is. exerted on shaftv 65.,

spring 82 returning the arm and; pin as. well as shaft 66 m neutral when the torque is no longer applied, that is, when the clutch isv disen aged.

the automatic pilot is engaged, rotor winding. 75

will only have a signal generated therein of; an amount proportional to the angle of deviation by the craftfrom the desired cmirseiv Element 2! of the magnetic field pick-up device together with itsprimary and; secondary windings is stabilized and maintained in ahorizontal plane by means .of a stabilizing gyroscope, or gyro vertical, generally designated with the reference character 85 so that a compass is provided in which, for all practical purposes, turning and acceleration errors are eliminated Upon a craft departure from a prescribed course, the voltages induced within coil 28 of the pick-up device are varied to vary the voltages at coupling stator 28 whereby a signal is induced within rotor Winding 3i, proportional to the amount of craft departure from its course, which is amplified within amplifier 33 to energize phase winding 35' of motor 37, the second, phase being continuously energized from the source of alternating current. Rotor all of motor 37 drives shaft 32 and rotor winding 3% 'to a null position, i, a, one wherein the electrical axis of the rotor winding is perpendicular to the resultant magnetic field of the stator windings, whereupon the induced signal drops to zero and motor 31 is deenergized. At the same time, assuming clutch faces 64, 65 to be in driving engagement, rotor winding 75 of transmitting device I! is moved angularly relative to stator windings I6 and a signal is induced therein proportional to the amount of craft departure from its prescribed course.

The electrical signal thus generated within rotor winding I5 is fed by suitable leads 86 to the input of a servo vacuum tube amplifier 81 and out therefrom by way of outlet leads 88 through a servo adapter 89 to energize one phase winding 98 of an induction motor 9|, the second phase winding 92 of which is continuously energized from the crafts source of A. C. current,

A driving connection between motor SI and rudder I2 is established by way of a servo clutch comprising a clutch face 93 mounted upon a shaft 94 carrying a pinion 95 for engagement with a speed reduction gear system 96 supported within a stationary servo casing 91 for driving a rudder shaft 98 connected by means of cables 99 with rudder I2, and a second clutch face I88 fastened to a shaft Ill! keyed to a gear I52 but adapted for longitudinal motion relative thereto, gear I02 connecting with a pinion I03 of motor SI through an idler gear I04. The free end of shaft IOI has an enlarged portion defining an abutment for one end of a spring member I05, the other end of which rests against gear I02.

The actuating means for axially moving shaft IBI to the right to force clutch face I05] to drivably engage clutch face 93 comprises a solenoid coil I06 grounded at one end by way of a lead I01 and connected to one of contacts II of servo clutch switch I2 by way of a lead I08. With switch I2 closed, a core H39 of the solenoid is urged to the right against the action of spring I95 to axially move shaft IfiI therewith to provide engagement of the clutch faces so that motor 9! drives rudder I2.

In driving gear I02, motor 9| also angularly displaces a rotor winding I II] of an inductive follow-back device having a three phase wound stator I I I, the rotor being supported by a shaft I I2 having a pinion II3 which is drivably connected to gear I02 through a speed reduction gear train II4. Displacement of rotor Winding IIU relative to stator windings III during operation of motor 9| generates an electrical follow-back signal which is fed by means of leads II5 to amplifier 81 through servo adapter 89 to be impressed upon the direction signal within the amplifier to thereby modify the operation of the motor. The

follow-back signal opposes the direction signal and at such times that the follow-back signal is equal and opposite to the direction signal motor 9| becomes de-energized.

As the craft departs from its prescribed course it develops a certain amount of angular velocity which is also taken into account in the control of rudder I2. To this end the rate gyro I3 is provided which comprises a rotor I I6 having normally horizontal spin axis supported by way of inner trunnions II"! within a gimbal ring II8, the latter being mounted upon a rigid support by way of trunnions I19 and I20 for oscillation about a second horizontal axis perpendicular to the spin axis. Resilient members I2I secured to trunnion II9 yieldably restrain gyro precession during turn to a rate of turn function. Trunxnion'l20 of yro I3 carries a gear sector I22 for meshing with a pinion I23 mounted on a spindle shaft I24 carrying an indicator I25 adapted for cooperation with a scale I26, as well as a rotor winding E27 inductively coupled with a three phase wound stator I23 of an inductive device, the rotor being connected for energization by the crafts source of A. C. current.

The windings of stator I28 connect by way of leads I25} with a three phase wound stator I323 of an inductive receiver device IilI (arranged at the novel controller unit to be presently described) likewise provided with a rotor winding I32 which is connected to adapter 89 by way of leads I33 to be there superimposed upon the follow-back signal to further modify the opera tion of motor sI when the craft departs from a predetermined course. Due to such departure, the induced voltages within stator I23 vary causing a corresponding change in the voltages of stator windings I36 whereupon a signal proportional to the rate of turn is generated within rotor winding I32 to be algebraically added to the direction and follow-back signals energizing phase winding 98 of motor 9|.

With the above arrangement, during an initial departure of the craft from a prescribed course, the rate signal adds with the direction signal and opposes the follow-back signal to hasten outward movement of rudder I2. The rudder is operated until the follow-back signal equals and opposes the rate and direction signals whereupon the motor is de-energized and the rudder has reached a definite outward position. The applied rudder causes the craft to come to a stop and swing back to its prescribed course at which time the rat signal drops to zero and then builds up again in an opposite direction to oppose the direc tion signal, which now diminishes, but adds to the follow-back signal until the rudder is returned to a neutral position at which time rotor winding I I G of the follow-back device is driven to a null and the follow-back signal drops to zero.

Except for the absence of the rate signal, substantially the same action takes place at the other two control axes of the craft. To this end, gyroscope I l comprises an artificial horizon which may have a horizon bar i mounted for up and down movement relative to a mask I35 for designating craft pitch, the mask, in turn, being adapted for angular movement relative to the bar for designating craft bank. The gyroscope comprises an electrically driven rotor I31 having normally vertical spin axis mounted within a rotor bearing frame I38 provided with inner trunnions I39 mounting the rotor and frame within a gimbal ring I40 for oscillation about a first horizontal axis, the gimbal having an outer trunnion I4I mounting it for oscillation about 2 second horizontal axis perpendicular to the Bank take-off I5 comprises an inductive transmitter device I42 having a rotor winding I43 carried by outer trunnion MI and energized from the crafts source of A. C. current, rotor I43 being inductively coupled with a three phase wound stator i 2 which connects by way of leads 45 with a three phase wound stator I46 of an inductive receiver device M'I (likewise arranged at the novel turn control unit to be presently described) having a rotor winding I48 inductively coupled therewith so that any change of voltages caused within stator I44 due to angular movement of rotor winding I43 creates a like change in the voltage of stator Mt whereby a ,signaliis induced within rotor winding I99 proportional to the amount of craft bank.

'Ihe signal induced within rotor winding I49 fed into amplifier 87 by way of leads I49 and fed out therefrom through servo adapter 99 by outlet leads I59 to one phase winding II of a two phase induction motor I52, the second phase winding I53 of which is continuously energized from the crafts source of A. C. current. Motor I52 constitutes a part of the aileron servo system 57 and a driving connection is established between it and ailerons I9 through a solenoid operated clutch which comprises two clutch faces I54 and I55, the latter being carried by a shaft I56 provided with a pinion I57 thereon for driving aileron shaft I58 through a speed reduction gear system I59 supported within a stationary casing I60, and clutch face I54 being carried by a shaft I 6I which has a gear I62 keyed thereto but is adapted for axial movement relative thereto. Gear IE2 is driven by motor I52 through an idler I63 which meshes with a pinion I6 3 carried by a motor shaft I65.

Clutch faces I54 and E55 are normally held disengaged by virtue of a resilient spring I58 which abuts gear I62 at one of its ends and an enlarged portion of shaft ISI at its other end to urge the latter shaft to the left. The actuating means for axially moving shaft I9! to the right to force clutch face I59 to drivably engage clutch face I55 comprises a solenoid coil I67 which is connected to conductor i9! at one end to ground and at its other end to contacts II of switch 72 by way of lead I68. With switch 72 in its on position, i. e., with contacts ii engaged, coil I67 is energized to urge a core I68 to the right against the action of spring I65 whereupon shaft I6I is moved to the right to bring clutch faces I54 and I55 into engagement whereby a driving connection is established between motor I52 and ailerons I9. 7

In driving gear I62, motor I52 also angularly displaces rotor winding I76 of an inductive follow-back device having a three phase wound stator I7I, the rotor winding being inductively coupled with the stator and being carried by a shaft I72 having a pinion I73 thereon which drivably connects with gear H52 through a speed reduction gear train I74. Displacement of the rotor winding relative to stator I'iI during operation of motor I52 generates an electrical follow-back signal which is fed by way of leads I75 to amplifier 87 through servo adapter 89 to be impressed uponsthe bank signal within the amplifier to thereby modify operation of motor I52, The follow-back signal opposes the bank signal and at such time that the follow-back signal is equal and opposite to the bank signal motor I52 becomes de-energized.

Pitch take-off I6 comprises an inductive transmitter device having stator windings I76 pro- Vided with three taps, the windings being energized from the crafts source of A. C. current by virtue of leads I77. A rotor H8 in the form of a magnetic vane is inductively associated with the stator and is secured to inner trunnion I39 for angular movement relative to the stator windings. Stator windings I76 connect by Way of leads I79 with a three phase wound stator I89 of an inductive receiver device (also arranged at the novel controller unit to be presently described) having a rotor winding I8I inductively associated therewith so that any change in voltages caused within stator windings I73 due to angular movement of rotor I78 creates a like change in the voltages of stator I89 whereby a signal is induced within rotor I8I proportional to the amount of craft pitch.

The signal induced within rotor winding I8I is fed by leads I82 to amplifier 87 and out therefrom through adapter 89 by way of leads I83 to one phase winding I86of a two phase induction motor I85, the second phase winding I86 of which is continuously energized from the crafts source of A. C. current.

Motor I constitutes a part of the elevater servo system I8 and a driving connection is established between it and elevator surfaces 20 through a solenoid operated clutch which comprises two clutch faces I87 and I88, the latter being carried by a shaft I89 provided with a pinion I99 thereon for operating elevator driving shaft I9I through a speed reduction gear system I92 supported within a stationary casing I93, and clutch face I87 being carried by a shaft I94 which has a gear I95 keyed thereto but is adapted for axial movement relative thereto. Gear I 95 is driven by motor I85 through an idler I 98 which meshes with a pinion I97 carried by a motor shaft I98.

Clutch faces I87 and I88 are normally disengaged by virtue of a resilient spring I99 which abuts gear I95 at one of its ends and an enlarged portion of shaft I94 at its other end to urge the latter shaft to the left. The enlarged end of shaft I94 is engaged by a core 298 of a solenoid whose coil 29I is grounded at one end by being tapped to lead I87 and its other end is connected :by way of lead I98 to one of contacts II of switch 72. With the switch in its on position, i. e., with contacts 7I engaged, coil 2M is energized to urge core 269 to the right whereupon shaft I98 is moved to the right to bring clutch face I87 into engagement with clutch face I88 whereby a driving connection is established between motor I 85 and elevators 29.

In driving gear I95, motor I85 also angularly displaces a rotor winding 265 of an inductive follow-back device having a three phase wound stator 296, the rotor being inductively coupled with the stator and supported by a shaft 267 having a pinion 268 which is drivably connected to gear I95 through a speed reduction gear train 289. Displacement of rotor winding 265 during operation of motor I85 generates a follow-back signal which is fed by way of leads 2IB to amplifier 87 through servo adapter 89 to be impressed upon the pitch signal within the amplifier to thereby modify operation of motor I 85. The follow-back signal opposes the pitch signal within the amplified to thereby modify operation of motor I85. The follow-back signal opposes the pitch signal and at such time that the followback signal is equal and opposite to the pitch signal motor I85 becomes de-energized.

With servo clutch switch 72 in an open or off position, even though power switch 74 is closed, coil 67 of the magnetic clutch within master indicator 30 is deenergized so that clutch face 64 is disengaged from clutch face 65 and simultaneously solenoid coils I66, I67 and ZIH. of the rudder, aileron and elevator servo systems are de-energized whereby motors 9|, I52 and I95 are disconnected from their respective control surfaces so that subsequent control of the rudder, aileron and elevator surfaces may be performed manually in the conventional manner.

Coming now to the novel automatic trim and/or turn controller unit constituting the subject matter of the present invention, the latter is shown schematically in Figure 2 as embodying an inductive bank device 2H having the wound stator I46 of Figure 1 and the inductively coupled rotor I48 carried by a shaft 2I2, an inductive rate device 2I3 having the wound stator I38 of Figure 1 and the inductively coupled rotor I32 carried by a shaft 2 I4, and an inductive pitch device 2I5 having the wound stator I88 of Figure 1 and the inductively coupled rotor I81 carried by a shaft 2 I6.

For the purpose of displacing rotor I8! of the pitch device 2 I relative to its stator I80 to thereby generate a signal for energizing the elevator servo system 18 to trim the craft in pitch, a pitch trim knob 2II is provided having a shaft 2I8 and carrying a cam 2I9 thereon for motion therewith. The shaft is arranged in such a manner that adjustment of knob 2H is obtained about an axis parallel with the axis of oscillation of the elevator. With the elevators in a centered or neutral position, a roller 220 rests against cam H9 at a point substantially representing a midpoint between the low and high points of the cam, the roller being rotatably supported by one end of a reciprocally movable rod 22I whose other end rotatably supports a second roller 222 thereon. Rod 22I passes through an apcrtured and relatively fixed plate 223 and carries a stop element 224 fixed thereto, a spring member 225 being provided between plate 223 and element 224 for urging roller 225 into intimate contact with the periphery of cam 2 I9.

Roller 222 is in engagement with a cam surface 226 carried by a lever 22? mounted for pivotal motion by way of a pin 228, the cam surface being formed by milling one end of the lever until a triangular cross section is acquired. By riding toward a high surface 229 of the cam, roller 222 will move lever 22'? in one direction about pivot 228 and by riding toward a low surface 230 of the cam the roller will move the lever in an opposite direction about its pivot.

The free end of lever 221 is provided with a slot 23I which receives therein a pin 232 fixed to a link 233 which connects through a shaft 234, journalled within a fixed bearing, with a link 235. The latter link pivotally connects with a lever 236 having a finger 231 engageable by one end of a sprin 238 which is anchored at its opposite end to a fixed pin 239, the function of the spring being to yieldably maintain cam surface 226 of lever 221 in engagement with roller 222. The free end of lever 235 pivotally connects with an arm 248 of a yoke member 24I, the other arm 242 of which pivotally connects with a link 243 which is engaged by one end of a spring 244, the opposite end of the latter being anchored to a fixed pin 245. Rotor shaft 2I5 carries a lever 245 which carries a pin 24'! loosely mounted in arm 242 of the yoke member.

In order to provide pitch trim, therefore, knob 2 I1 is displaced angularly together with its shaft 2 I 8, which is journalled within fixed bearings, and cam 2I9 whereupon roller 228 is caused to linearly displace rod 22I against the yieldable action of spring 225. As a result of linear displacement of the rod, roller 222 rides upon or down on cam surface 226 to move lever 221 in one direction or another about pivot 228, the latter angularly displacing links 233 and 235 through pin 232. Angular motion of link 235 manifests itself in up or down movement of lever 235 whereupon yoke member MI is moved up or down about a then fixed pivot defined by the connection between arm 242 and link 243 to angularly displace shaft 2I5 and rotor winding I8: through the connection defined by lever 246 and pin 251. Depending upon the direction of displacement of rotor I8I relative to its stator either an upelevator or a down-elevator signal is developed in the former for elevator trim and communicated through amplifier 8! to the elevator servo system I8.

For the purposes of displacing rotor winding I48 of the inductive bank device 2H relative to its stator M5 to thereby develop a signal for energizing the aileron servo system I? to trim the craft in bank, a bank trim knob 248 is loosely sleeved on a turn shaft 243 and is provided with a pin 258 for engagement with one end of a lever 25l mounted for pivotal motion by way of a pin 252 journalled within a fixed bearing. A spring member 253 normally urges lever 25I into engagement with pin 253 and the opposite end of the lever is provided with a slot 254 which receives a pin 255 therein fastened to a link 255, the latter being carried by a shaft 251 which is journalled within suitable bearings, the free end of the shaft carrying a pinion 253 thereon.

Movement of bank trim knob 248 is communicated to rotor winding I 48 through a differential gear system 259 which comprises a cage defined by a pair of spaced parallel annular members 258 and 28I which are interconnected with each other through one or more bolts 26Ia. Member 268 is formed with a toothed periphery for drivable engagement by pinion 258 and is sleeved about a hollow shaft 262 carrying gears 253 and 234 at each of its ends, gear 263 meshing with a gear 285 fixed to the free end of turn shaft 249 and gear 264 meshing with a pinion 285 which is rotatably mounted by way of a shaft 251 journalled within members 288 and 28L Pinion 285, in turn, meshes with a second pinion 253, which is rotatably mounted by way of a shaft 259, also journalled within members 283 and 25I, the latter pinion drivably engaging a gear 219 fixed to the free end of rotor shaft 2I2, the latter shaft passing through hollow shaft 282.

Thus, movement of bank trim knob 248, in one direction or another, displaces lever 25I about its pivot 252 to oscillate pin 255 and thereby angularly displace shaft 251 whereupon pinion 258 drives member 258. Since gear 265, at this point, is locked against rotation by shaft 249, movement of member 260 causes pinion 265 to creep on gear 254. The pinion, in creeping, drives pinion 268 which, in turn, drives gear 210 and shaft 2I2 therewith to angularly displace rotor I48 relative to its stator. The signal induced within the rotor is fed to the amplifier and out therefrom to aileron servo system I! for bank trim.

In order to place a shaft provided with the all electric, automatic pilot hereinabove described into an automatic turn, turn shaft 249 is provided with an elongated handle 2II of a pistol grip type which, when displaced, angularly displaces wound rotors I32, I48 and IBI of the rate, bank and pitch devices 213, 2 and 2I5, to thereby provide the correct rudder, aileron and up-elevator signals for the turn selected, such signals being developed independently of the master instruments I0, I3 and I4 normally controlling the automatic steering system hereof.

Displacement of pistol grip handle 2' causes displacement of shaft 249 and gear 285 secured thereto. As a result of such displacement, gear 265 drivesigearsitiiand 26 3, the latter rotating pinion 266, member, 269 being locked against rotation at this 'point by pinion 258 operable from bank "trim knob" 248. Pinion r 268 drives pinion 268 which, in trirnjdr'ives' gear 279 to displace rotor hi8 and thereby develop therein the required aileron signal for the selected tiirn. In addition to rotating gear 265, turn shart'zse alsorotatesa pinion 212 "secured thereto which meshes with a gear Z'EB haVing a pinion 274 fastened tlieretd and in driving engagement'with a gear sector L275 whichis fastenedto shaft 2'i4. Thug friction of shaft 249 likewise causes displacement of wound rotor I32 relative 'to its statorso that a signal is dev'eloped within the roteriorgcomrnunication to the rudder, the signal being of the character required for proper rudder displacement for't he turn selected.. I I V lso secured to shaft 2 iy4 ior r'noveinent during motion of s ector z'Iifi is a link Q215which pivotally connects with a lever 21?,the free end of which is pivotallyconnected tothe free end of link 2431. A midpoint of thelever is provided with'la pin 2 l8 supporting a r Ol ler Z'I Q 'theijeon, the rollerf being yis sa urged, i o. a e-sw e w t a Pitch can adj us tinent systerri to belpresentlydescriced t ey elsb mem r 280 c e f t 91 endt o l i 1l 216 andat its other end to a fiXed pin ZB L Motionoipinion 2l2 thereiore causes dis- I placement or link 215 in either direction to inove leveifi Z'I 'I to, the leftfior right but; because I of its engagernentwith the pitch cain system, theoppo- .si tefIend of the lever al ways'Im'oves downwardly to mo ve link 2'43 'therewith and therebyfdisplace :yqlsememb downw s about a h n s pivot'ldefined by theconnection of lever 233 and aim 2. 9- Q I; th s anns rr t i8 is di e accr di st rs p idet j trs tuptelevatgrsignal for either direction of turn se- I h e by .h l p smfi nilzf h iish P m diu m t s t m s e i edl abov is :providedto insureproper initial setting s l i H521 h re -t r s r rates 10 urIiu either a left or right direction enough d i s placeree t r we: 1 w lib P i ed t maintain t e cra t in level it during t ral r I iir v tl'a ee-n w l s o att t d n tion during a given ti1 rn The adjustment cornprisesthe roller 21$: carried .by leve r 217 which is i1r'ged into engager ent with a pair of cams 2 82 IandIZES t he former being fixedto a shaft 284 stratus latter; being jhollow 'and sle eved on the fsiiartand provided with a gear 285 for m eshin I i'eisiiartzaz. Adjustnie'ntiof the two dams defines the limit of downward thrower roller 1219 for a giv'enileft'or rightTrnotion'of lever 27? and consequently the'arnou'nt of'd'i'splacement' of rotor ,eiigagerxientlf with longitudinally movable cones 290 and zeliieiisag'ea by ad usti g screw/ 1292. and V 293. r The screwsi are' providedpwithfstraps" 294 and 295 whichfnorrnallyhlock1screws'f2'92l andi293 in a given position but'upon loosening of Tother In addition to driving gear 265 and pinion ZIZ,

7mm shaft 249 also displaces an annular notched dise"2'98 within wnose' notch normally rests a 12 and yieldably urged to engage the notchlby' means of a yieIdablemember'StZ. .When turn shaft '249 is displaced angularly, arrn'filln'is urged outwardly whereupon detent'ESQ leaves the notch wh ile the opposite end of the arm,- provided] with a contact (not shown) is movedjclownwardlyflto open apair] of contacts (not shown), arranged within a conventional switch box 303, which normally connect coil 61 of the'magneticclut'ch figl, 65 at the Vmaster indicator with battery 69 through conductors 3534,3135. Q'peningof the contacts withinhox 303 by angular displacement of shaft z wjtherefo're, de-energizes coil' fil so that direction signal from the inductor compass is'disconnected during a turn from the rudder servo channel at which] time the latter channel is energized by the signaldeveloped within rotor 132 ofdevice2l3. II I I I In response toinitial displacement of turn shaft 259 signalsfareimrnediately available within rotors I48, I32 and [8| for aileron, rud'denand elevator control but some small time interval elapses prior to the opening of the contacts within switch box 393 so that theinductorc-ompa ss will still control rudder, such time interval ari sing due to the fact that a given angular movement of shaft 249 is required before the, switch' is opened. aresult, aileron and elevator surfaces will be deflected to cause the craft to crab momentarily before the SWllJCh lS opened to deenergize coil 51 and thereby disconnect the rudder from the compassat which time rotor !32 takes over to control rudder deflection resulting in uneven craft flight. II I II I II I To the end'thatsmootherflight asfwell' as finer rudder'trim' rnay beobtailned, a second switch fiflfi is provided connectedin series with switch .303, the fformericomprising a pairofcontacts' :tfi'lj'and 308 normally closed by abridgi'ng 'contact 309. yieldably urge to a closed position smoother 'fiight in 'turnthan that heretofore available, After ag'iven'd'isplacernent of the handle, switch 393 is" likewise openedisothat du'ring the jturn the triggerinaybe released so' that switch 305 will again"be"closed but since'swit'ch 303 is opened the coil '61 will 'reinainde-energi'zed until handle 21! is centered atthe'coinpletionof craft turn. I I l It willnowbe' app'arent'tliat by g'raspingpistol gri 2H and depressingtrigger 3i3fthe inductor compass will be disconnected frorn'the 'rudder and th'atjbank, 'rate and 'pitch signals are developed inductive devices 2 I I, 2! an 2 mindependently of their respective" master instruments whereby the aileron, rudder and elevatof'suriaces are deflected the proper amount "to place thecraf t in a turn attitude, snrfaced'eilection continuing until the follow' back signals ofinductive devices :1 0+" 1 g, 176 Land zes zas (Figure 1)" are 'edIial and op-pQsite to' the bank, rate'and pitch sigiia ls' of devices 21 is 'and'Zi'S. Asthecorrect craft attitude is attained, signals are generated by the master instruments, 1. e., bank take-off I5, rate take-off I21-I28 and pitch take-off I6 to Wash out the signals developed by devices 2II, 2I3 and 2I5. The follow-back signals, at this point, being at a maximum act alone in reversing servo systems I I, I1 and I8 to center therudder, aileron and elevator surfaces, the craft remaining in the desired banked attitude. Moreover, should the craft depart from such attitude the master instruments will operate to return the craft to the desired attitude. Once the new course is attained, turn handle 21I is centered manually to set the craft on the new course and switches 333 and 306 are closed to energize coil 51 of clutch Ed, 65 of the master indicator whereby the compass takes over and maintains control of the rudder.

One practical embodiment of a controller unit for operating the nOVel mechanism of Figure 2 is shown in Figures 3 and 4 and, as there illustrated, a housing 320 is provided for enclosing; the mechanism of Figure 2 which is supported by a casing (not shown) arranged within the housing and having a flange 32I provided with openings 322 for securing the unit to the craft either in a horizontal or vertical plane as desired. Secured to the upper front end of housing 320 is a hollow outwardly extending arm 323 supporting at its outermost end a pitch trim knob 324, corresponding to knob 2I1 of Figure 2, for angular motion therein about an axis parallel to the craft transverse axis and the axis of elevator control. This arrangement is of aid to the human pilot since movement of the pitch trim knob will be the same as the movement imposed on the elevator by a conventional control column, i. e., rotation of knob 324 toward the pilot will provide an up-elevator condition while rotation of the knob away from the pilot will provide a down-elevator condition.

Inscribed at the outer end of arm 323 is an index marker 325 which cooperates with an index 326 inscribed on the outer periphery of the knob, a, no signal condition for rotor I8I and a neutral or central position for elevator 20 being manifested by alignment of markers 325 and 326. Downward motion of knob 32A and its jmarker 326 relative to fixed marker 325 angularly displaces rotor I8I of device 2I5 to provide an up-elevator trim condition in the manner described in connection with Figure 2 while upward motion of knob 324 and its marker relative to marker 325 displaces rotor I8I in an opposite direction to provide a down-elevator trim condition.

Mounted for angular displacement about a central axis of housing 320 is a hollow bank trim knob 321 which corresponds to trim knob 248 of Figure 2, the knob being provided with an index 328 for cooperation with a fixed index 329 carried by a bracket 333 fastened to flange 32!. Motion of knob 321 in one direction relative to index 329 displaces rotor I43 to provide right bank or aileron trim while motion of the knob in the opposite direction to the index displaces the rotor to provide left bank or aileron trim, coincidence between indices 328 and 329 indicating a no signal condition for rotor I43 and a centered or neutral position for the ailerons. "Fixed with respect to casing 320 is a pin 33! l which extends into knob 321 to be engaged by one or the other of pins 332 or 333 carried by the knob and thereby define a limit of motion for the knob in either direction of rotation.

.. Bracket 330, moreover, rotatably supports a shaft therein corresponding to turn shaft 249 of Figure 2 which passes through knob 321, the free end of the shaft passing through a sleeve 334 and having a pistol grip handle corresponding to handle 2' of Figure 2, attached thereto. The inner side of the handle is apertured to accommodate a trigger 336, corresponding to trigger 3I3 of Figure 2, in the manner and for the purpose described in connection with the arrangement of Figure 2.

Motion of pitch trim knob 324 in one direction or another about an axis parallel to the axis of elevator motion displaces rotor I8I of device 2I5 to develop a signal therein for elevator trim. Motion of bank trim knob 321 in one direction or another about an axis parallel to the craft fore and aft axis provides displacement of rotor I48 of device 2 to develop a signal therein for left or right bank trim. By grasping handle 325 and depressing trigger 336, the compass is disconnected from the rudder channel and subsequent angular displacement of the handle provides displacement of rotors I48, I32 and I8I of devices 2, 2I3 and 2I5 whereby aileron, rudder and elevator control signals are developed therein for turning of the craft. Following a small displacement of handle 335, switch 303 is opened so that trigger 333 may be thereafter released.

The novel automatic trim and/or turn controller mechanism hereof and the automatic steering system controlled thereby is of such character that extreme flexibility of control is provided thereby which makes it possible to execute maneuvers by turning appropriate controls on the unit. For example, sharply banked turns may be made by actuation of pistol grip handle 333, the craft immediately assuming straight flight when the handle is returned to its central position. Bank and pitch trim is immediately available upon operation of knobs 324 and 321. Steep climbs or dives may be made by operating pitch trim knob 324. Also, a combination of turns and climbs or turns and dives may be exeouted or the craft quickly thrown from a correctly banked turn in one direction to a correctly banked turn in an opposite direction.

Although but a single embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention, as the same will now be understood by those skilled in the art.

I claim:

1. In an aircraft automatic pilot for controlling rudder, aileron and elevator surfaces and having course change responsive means, rate of course change responsive means and attitude change responsive means, said first two named responsive means controlling said rudder, and said last-named responsive means controlling said aileron and elevator surfaces, the combination with said pilot of a controller unit therefor, said rate of course change responsive means comprising a rate of turn gyro and an electrical takeoff therefor together with a repeater device con nected to said take-off, said repeater device co1nprising a stator arranged at said unit and an angularly movable rotor inductively associated with the stator, said attitude change responsive means comprising an artificial horizon gyro and electrical bank and pitch take-offs therefor together with repeater devices connected to said bank and pitch take-offs, said repeater devices compristol grip-handle adapted for angular motion about an axis parallel with the crafts fore and aft change responsive means from said rudder, said instrument providing a signal in" response to the repeater-devices, and a trigg'e'r on said h'andle'for disconnecting said course change res onsive meansfrom said rudder. H I

2. In an aircraft automaticpilot for controlling a craft rudder arid having course change re- 7 sponsive means and rate of turn responsive means connected for actuatingsaid rudder, said rate of turn responsive means comprising a rate of turngyro and a take-01f therefor together with a repeater connected thereto, the combination with said pilot of means comprising a :pair of normally closed --interconnected switches arranged between said'c-ourse change responsive means andsaid" rudder, means comprising-a pisaxis for actuating said repeater device independently of said take-ofi'ior controlling said rudder and for op'eningone of said switches to disconnect said coursechange responsive-means from said rudder, and a trigger pivotally sup- :ported on said handl'efor movement about an axis normal to the'pivotal'axis of the handle for openingthe other of said switches prior-to'angular displacement of said-handle.

3; In an aircraft automatic pilot'for controlling a craft rudder and having course change responsive means and rate of turn responsive means connectedfor actuatlng said rudder, said rate of turn responsi'vemeans comprising "a rate of turn gyro and a take-oil therefortogetherwith 'a'repeater connected thereto, the combination with said pilot of m'ean's comprising a pa ir of normally closed serially interconnected switches arranged between said course change resp'onsi've means and said rudder, a controller unit for said pilot, "a substantially I hollow pistol-grip handle pivotally-supported-- by said a unit for angular displacement about a single axis parallel with the craft fore and aft axis whereby'in-response to displacement'of said handle-said=repeater device is actuated independentlyofsaid take-ofi for controlling said rudder'andfor'opening one of said switches todisconnect'said course handle having an opening therein facing said unit, and means" comprising a'triggerpivotall'y mounted Withinthe opening of said handleab'out an axis normal to'the pivotal axis of the'handle "for opening the otherof said'switches priorto angular displacement of said handle.

4. In an aircraft automatic "pilotionoperatinga control surface about" an axis "parallel with the'crafts transverse axis'and having'a"master departure by said craft from'a' predetermined attitude about its 'transverseaxis together-with means connected to said instrument'for "normally repeating said signal to actuate said" surfacei to return said craft to said' predetermined attitude,

the combination with said pilot of a controller unit having an outwardly extending arm, and-a pitch-trim -knob supported in=said armior angu 'lar displacement about an axis parallel to the axis-of motion-of said surface wherebyin response'to' displacement of said knob said-repeater means is actuated so that-the-same movement is imposed on'said surface as that imposedon said knob.

5. 'In I an aircraft" automatic pilotfor operatin a"controlsurface about an axis'parallelwviththe crafts transverseaxisand having a master "instrumentprovi'ding' a signal in response to the departure'by said craft'f'rom afpredetermined attitude about its transverse. axis together with means connected to said instrument for normally repeating said signalto actuate said surface toi'return sai'd craft to said predetermined attitude,

the combination with "said "pilot of a controller unith'avingjan outwardly extending, arm, an inde xma'rker on said arm, ajpit'ch trim knob for actuating said repeating means' supportedin said arm'for angulardisplacement about-an 'aXis' parallel to the axis of movement'of saidsurfaca'fan'd an index marker on said 'knob for cooperation with said' first'index marker.

6. A pitch trim control for anautomatic (pilot for aircraitaprovided with an elevator movable about a transverse axisof the craft comprisin'gja casing, an arm securedto saidcasing "for extension outwardly therefrom.and'llavin'gv a bi furcate'd end, a pitch trim knob rotatably mounted'onisaid arm within said bifurcation iormotionabout an axis parallel to said craft-transverse axis, anindex on'said arm, a cooperatingindex on'sai'd knob, means withinsaid casingfor developing -a signalfor actuatingsaid elevator, andmeansconnecting said last-named means -tosaid-knob whereby motion ofthe knobinonefdirection relative to said fixed index provides an -up-elevator .conditi-on while motion-iof-the knobin'anwopposite direction relative to said fixed index providesa down-elevator condition.

'7. A controllerunit for an automatic-steering system for aircraft co nprising a casing, meansal ranged within-said casing for controlling said craft in direction, -pitch and bank, means'forlprosvidinga nose-up or nose-down condition for said craft comprising an elongated arm secured to said casing and-extending outwardly therefrom, a trim knob for actuating said pitch control means supporte'd at'the free end ofsaid. ar-mfor angular motion about an axisiparalll withlthe craft transverse axis, means for provi'ding a left bank or a right bank for said craft -comprising akncb'for actuatingsaid" bank control means arranged below said for angular motion about an axis parallel With-the craft fore and aftaxis,

and means 'for providing an automatictumfor said craft comprising an elongatedlpistolagrip handle 'for. actuating, said direction, f-ipitchi and bank control means superimposed over said'last- "named knob for angular. motion about an? axis Coaxial with said last hamedikhob.

8. A controller-unit 'for'an 'automatic steering system for aircraft comprising a casingfmea'iis arranged within saidbasing ror controlling said "craft in bank;pitc'h anddir'ection, means comprising a'knob for act'liatin'g sai'd'bank contrdlli'ng 'means-supported on sai'd casingifor angular-motion about a substantially.icentral axis of said "casing paral'lel. with "the "craft fore and aft axis, means comprisingfa 'n elong'ated' arm securewto said casing and extending outwardly the'refrom "over said knob, asecond' knob'ior' actuating said pitch controlling means supported at the free end of said arm for angular motion about an axis parallel with the craft transverse axis, and a pistol grip handle for actuating said bank, pitch and direction controlling means in unison supported on said casing below said arm for angular motion about an axis coaxial with the axis of said first nazned knob.

9. A controller unit for an automatic steering system for aircraft comprisin a casing, means arranged within said casing for controlling said craft in bank, pitch and direction, means comprising a knob for actuating said bank controlling means supported on said casing for angular motion about a substantially central axis of said casing parallel with the craft fore and aft axis, means comprising an elongated arm secured to said casing and extending outwardly therefrom over said knob, a second knob for actuating said pitch controlling means supported at the free end of said arm for angular motion about an axis parallel with the craft transverse axis, and an elongated pistol grip handle for actuating said bank, pitch and direction controlling means in unison and supported on said casing in spaced relation to said first-named knob for angular motion about an axis coaxial therewith and being movable in a plane substantially coincident with the plane of motion of said second-named knob.

10. Control means for the elevator surface movable cam member, a reciprocally movable member for displacing said cam member, and means comp-rising a cam operated by ustment of said knob for displacing said reciprocally movable member.

11. Control means for the elevator surface of an aircraft comprising a casing, a signal genera tor arranged within said casing for controlling said surface, a trim knob mounted for angular motion on said casing for actuating said genera tor, and means connecting said knob to said generator comprising a pivotally movable cam memher, a reciprocally movable member for displacing said cam member, and means comprising a cam operated by angular motion of said knob for displacing said reciprocally movable member.

12. In an aircraft automatic pilot for controlling a craft surface and having course deviation responsive means connected for actuating the surface, the combination with said pilot of a turn controller therefor comprisin course change means for operating the surface, a pair of normally closed serially connected switches for making the course deviation responsive means efiective on said surface, a substantially hollow pistol grip handle connected to the course change means and pivotally supported by the controller for angular movement about a predetermined axis to actuate the course change means and for opening one of said switches to make the course deviation responsive means ineffective on said sur-' face, said handle having an opening therein facing the controller, and means comprisin a trigger pivotally mounted within the opening of the handle about an axis normal to the pivotal axis of the handle for opening the other of said switches.

13. In an aircraft automatic pilot for controlling rudder, aileron and elevator surfaces and having course change responsive means and turn means for controlling a selected one of said surfaces together with attitude change responsive means and bank and pitch signal generators for controlling aileron and elevator surfaces, 21. control mechanism being provided between the course change responsive means and the surface controlled thereby for normally operatively con necting the course change responsive means with the selected surface and being operative for disconnecting the course change responsive means from the selected surface, the combination with said automatic pilot of control means therefor comprising a pistol grip member mounted for pivotal movement about a single predetermined axis for operating said turn means and said bank and pitch signal generators to vary the course and attitude of the craft, switch means connected with said control mechanism for operating the latter, said switch means being connected for operation by movement of said pistol grip member whereby the control mechanism is operated to disconnect the course change responsive means from said selected surface, and a trigger mechanism carried by the pistol grip member operably connected with said switch means for also operating the latter to operate the control mechanism to disconnect the course change responsive means from the selected surface.

14. In an automatic pilot for controlling a craft surface and having course change responsive means and displaceable turn means connected for actuating said surface together with a control mechanism normally connecting the course change responsive means with the surface and operable to disconnect the course change responsive means from the surface, the combination with said pilot of control means comprising a pistol grip handle mounted for pivotal motion about a predetermined axis, a pair of switches operably associated with said control mechanism controlling the operation thereof to disconnect the course change responsive means from the surface, a trigger pivotally mounted on the handle for movement about an axis normal to the pivotal axis of the handle, means connecting the handle to displace the turn means and to operate one of said switches whereby said control mechanism is operated to disconnect said course change responsive means from said rudder, and means connecting the trigger to the other of said switches for operating the latter whereby said control mechanism is operated to disconnect the course change responsive means from the surface- F. HENRY s. ROSSIRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,144,616 Carlson Jan. 24, 1939 2,351,977 Kronenberger et al. June 20, 1944 2,401,168 Kronenberger May 28, 1946 2,415,429 Kellogg et a1 Feb. 11, 1947 2,415,430 Frische et a1. Feb. 11, 1947 2,416,097 Hansen et al Feb. 18, 1947 2,481,776 Osborn Sept. 13, 1949 2,516,796 Noxon et a1 July 25, 1950 OTHER REFERENCES Handbook of Boeing Aircraft Co. (D-2664, copyrighted 1940) for maintenance of the Boeing Stratoliner, Model S-307; page 82.

Popular Science of June 1945; page 81.

Electronics of October 1945; pages 98, 99, 100, 101. 

